A system is known that is called a HEMS (Home Energy Management System) which connects electrical units installed in a home to a communication network, and which integrally manages the units by a controller. In recent years, as disclosed in, for example, Patent Literature 1, a HEMS is also known which can remotely operate units installed in a home via, for example, the Internet from outside of the home even if a user is not home. According to Patent Literature 1, the units can be remotely controlled, and the system makes a query to the user requesting an approval prior to the execution of the remote operation, and, when the approval is given, the system executes the remote operation.